The Promise
by Cybercitizen
Summary: When they were little kids, Elsa and Anna made a promise to each other. Thirteen years later, Anna discovers her old diary and remembers that very promise. (Elsanna, Canon, Fluff)


Once again, the halls of Arendelle's castle were filled with the sound of two young girls giggling. As they ran through the halls, Princess Elsa and her younger sister Anna, threw snowballs at each other, laughing as they hit each other in the face.

They were playing with Elsa's powers, magic gifts which neither of the girls could explain, yet had fun all the same. As Elsa chucked another snowball at Anna, the younger girl ducked for cover, smirking. "You missed me, Elsa!" She cheered.

"I'll get you this time!" Elsa declared, before conjuring a really big snowball in her hands and tossing at Anna. The massive snow-boulder travelled through the air before crashing down atop Anna with a soft thud, burying her under it.

Elsa then ran towards the snowball, as little Anna dug herself out of it, her hair full of white fluff. As she looked at her sister, she giggled. "You win!"

"You stinker!" Elsa replied, booping the younger girl in the nose. She then held out her hands and quickly melted all the snow and ice around them covering their tracks so they wouldn't get in trouble. That was one of the many perks of having such magic powers.

After getting out of the kitchen to sneak some chocolate, the two sisters headed towards the garden for some more playtime. Thankfully, they didn't have any of their lessons today, since being princesses came with a lot of duties.

As Anna wiped her fingers free of chocolate stains, she heard something coming from a nearby room. It was voices, slightly muffled voices.

"Psst, Elsa," Anna said, tugging her sister's shirt. "I think there's a ghost following us."

Elsa giggled, being the wiser and logical of the two of them. "Don't be silly, Anna. There are no such things as ghosts."

"But I heard a weird noise," Anna insisted, before both of them heard the noise again. Elsa raised an eyebrow and followed the noise to a nearby room in the castle. Creeping up to the door of the room, Elsa poked her eye in through the keyhole, wondering what the noise was.

It was, in fact, two people talking, namely, Elsa and Anna's parents. The room in question was obviously her father's private study, and their parents seemed to be in the middle of a conversation, about something, Elsa wasn't very clear about.

"What is it?" Anna then wondered. "Is there a ghostie in there?"

"No, it's just Mama and Papa," Elsa replied. "Come on, let's go and play in the garden."

"Wait! What are they talking about?" Anna then asked. "We should listen in! I always wonder what Mama and Papa talk about."

"Anna, you know we don't understand grown-up talk," Elsa then told her sister cautiously. "If we get caught out here, we could be in big trouble."

"Please!" Anna begged, putting her little hands together. She then gave Elsa her famous pouty face, the one the older girl could never resist.

Feeling guilty upon seeing Anna's wobbling lip, Elsa sighed. "Fine... but stay quiet okay?" she then said, slight worry in her voice.

Anna made a zip motion on her lips, which made Elsa smile, and the two little girls headed to the side of the door, pressing their ears against the wood as they eavesdropped on their parents' conversation.

"Yes, Elsa is certainly going to be a natural leader when she grows older," their father first said, his voice soft and kind, yet firm at the same time. "When she becomes Queen, she'll no doubt rule Arendelle just as good as I have done, Idunn."

"That's quite true, Adgar, but we shouldn't pressure the girl so much with her studies," their mother then replied. "She's still a child after all. She needs to be more like an ordinary little girl than some princess. You know that's what we agreed when we decided to have her."

"I know, but I am only praising her for what she has shown so far," the king told his wife, a smile on his lips. "Her tutors are saying she and Anna are model students, the best they've ever had. I think we've truly raised some wonderful daughters, Idunn."

"Yes, we have dear," the Queen agreed. "But I worry that if we start putting Elsa in the spotlight more, we might leave Anna behind. I know we mainly had her to give Elsa a friend, but at the same time, they're both our little girls. I want them to remain equal."

"As do I. But Elsa is the elder child and she's the first in line to inherit the throne after us. We have to make sure she's ready, Idunn. You've heard how there's been a revolution in the Southern isles and that Corona recently lost their heir. I don't want something to happen to Arendelle and for our children to not be prepared for it."

"I'm not saying we stop preparing our daughters, dear," The Queen insisted. "All I'm saying is that we need to tread carefully with this, especially when the girls start getting older and they need to have suitors."

Anna felt confused after she heard that word. It was a word she hadn't learned before, not from lessons or her parents. As they continued to listen, Anna tugged her sister's shirt. "Psst, Elsa."

"Shhh, I'm trying to listen," Elsa replied.

"But I wanna know what that word means," Anna whispered. "What does that suutor word mean, Elsa?"

Turning away from the door, Elsa sighed. She did know what that word meant, but she knew it might upset Anna. The young girl had such big dreams for her life and she didn't wish to be the one who shattered them for her. She couldn't do this to Anna, but she knew the little girl wouldn't stop asking about it.

With a heavy heart, Elsa pulled Anna away from the door so she could confess what she knew about Anna's word. "Well... Okay," she spoke, nervously. "You know how Papa always says it's my duty to one day become queen, right?"

"Yeah, but they never told me what my duty is," Anna replied. "I always thought it was for me to always be your best friend."

Gulping, Elsa spoke again. "Well... your duty is to be my best friend... but it's also to be a princess. You know how babies are made right?"

"Yeah, a boy and a girl get together, hug really tight and then one appears?"

"Yes... well, for us, we need to have that boy chosen for us. It's not like in fairy tales where one magically comes to our rescue, Anna." She sniffled. "I'm sorry... but that's how it has to be."

Hearing the news at Anna's young age broke the little princess's heart. Her dreams about being carried off by some handsome prince were dashed completely. In seconds, the little girl broke down in tears, crying her little eyes out and running into Elsa's arms.

Stroking Anna's hair, Elsa tried her best to comfort her baby sister, but she knew it was her own fault for telling her. She should have just kept quiet about it and let Anna discover on her own. But if Anna had done, would that only have made her more upset.

It didn't matter now, the damage was indeed done and Anna was crying in her arms. The younger girl clung to Elsa's side, her eyes wet with tears.

"That's so not fair," Anna sobbed. "I don't wanna have my prince chosen for me! I wanna chose my own prince, who will love me and care for me and I wanna be your best friend forever too!"

Realising she had to make the best of a bad situation, Elsa then had an idea, one that would cheer them both up. "I have an idea!"

"Y-You do?" Anna wondered, sniffling a little. "W-What is it?"

Elsa smiled. "It's simple. When I become queen, you can be my princess. We can rule Arendelle together and no prince will ever have to get near you."

"Y-You'd be like my prince?" Anna said, softly.

Her big sister nodded. "Yes, I will... and if you ask me, Anna, girls are a lot better than boys!"

"That's true!" Anna chirped, letting Elsa wipe her tears. "I'll be the best princess for you ever, Elsa!"

Grinning, Elsa booped her little sister on the nose. "So... you wanna go build a snowman?"

"Yes please!" Anna cheered, before taking Elsa's hand, happy that she was going to always be with Elsa for the rest of her life.

xXx

 _Thirteen Years Later_

Princess Anna was sifting through her old things in her bedroom, doing some spring cleaning for the first time in many months. She knew she could have asked one of her maids to do it, but Anna found her bedroom to be very special indeed. Full of so many memories of a past that had many ups and downs, this room was a sacred place to the young princess.

But things were going to be changing soon. Now that she and her sister, Elsa, were reunited again, they had decided to share a room again, just like they had done as children and Anna wanted to make sure everything was ready for when the queen moved in.

As she made her way through many boxes and cupboards, finding old things such as old hair clips, baby teeth and even a small little bicycle, Anna let waves of nostalgia flow through her. Her separation from Elsa may have been painful, but some good had clearly come from it all.

When Anna opened a small box in the corner of the room, she was met with a sight she hadn't seen in so many years. It was a little book, with her name on the front and the word "Diary."

"My old diary!" Anna expressed with glee. "I thought I had lost this years ago." She picked up the little book and placed it on her lap. "Gosh, I definitely can't have this put up in the attic." She then turned the pages, smiling. There were loads of little entries, all from when she was very, very small.

It was all written in her handwriting, which was a lot worse than it was now, but Anna could still read it. Her lessons over the years had taught her how to understand many languages after all.

Continuing to browse the old entries, Anna smiled. "God, I was such a cute little kid... oh wait, I still am." She giggled and turned the page again. As she looked at this page, Anna looked closer at the entry that was written upon it, along with a small doodle drawn by her of Elsa and herself holding hands. Unlike all the other entries in the book, this one Anna didn't seem to have any memory of.

"Was this just before I had my accident?" She wondered aloud. That would explain why she couldn't remember the event. Her accident as a child had led the trolls in the valley of living rock to erase most of her memories of Elsa, so this could have been among them.

Reading through the page, Anna's eyes widened with glee. It was of a time when she and Elsa were little and the young princess had learned about love and how she would one day be matched up with a suitor. This brought back some uncomfortable feelings for Anna.

All her life she had hated the idea of being matched up with someone, but ever since the experience with Hans, Anna was wondering if being paired off by someone else was a better option.

Reaching the bottom of the page, Anna found a small little passage that made her eyes widen with surprise. This surprise then gave her an idea, an idea she should have had so many years ago. Quickly, she held the book in her hands and darted out of the room as fast as her legs would carry her.

Running through the corridors of the castle, Anna eventually found her sister Elsa, striding through the garden peacefully, wearing her gorgeous ice dress. Running out to Elsa, Anna called to her with excitement. "Elsa! Elsa! Elsa!"

The Queen turned around, giggling a little as her little sister ran towards her. "Anna? What's the matter? You seem excited about something."

Anna grinned and held up the book in her hands. "Look what I found up in my room, Elsa! It's my old diary, the one I wrote in as a kid."

"Oh," Elsa said, pleasantly surprised. She took the book off Anna's hands and opened it up, reading the contents of what was inside. "I completely forgot you had a diary, Anna. Wherever did you find this?"

"In my room," Anna stated. "But that isn't the best part." She then flicked through a few pages on Elsa's behalf, finding the page she had just read previously. "Read this."

Elsa looked closely at the page, before she read it to herself.

 _Dear Diary_

 _Today was a good and a bad day. It was bad because I found out a new word that I really don't like. Suutor. Elsa says it's someone who Mama and Papa have to choose to be my prince one day. I don't like it. I want to choose my prince, but Elsa says that can't happen. But that's when it got good. Elsa promised me that one day, if she turns queen, she'll make me her princess. That's so cool! I can't wait to be Elsa's princess! I love her so much!_

A small smile crept onto Elsa's face. "I... I had forgotten all about that. I remember you got so upset, so I promised you that I would always be there for you."

"Yeah," Anna blushed. "And I just kinda realised. You're Queen now and I'm a princess and we're back together and..."

Giggling, Elsa looked at Anna. "What are you getting at, Anna?"

"I'm saying that... we should fulfil that promise, Elsa!" Anna chirped, taking Elsa's hands. "I want to be your princess for real." She then closed her eyes, before giving Elsa a loving gaze. "Elsa... My sister... Will you marry me and make me yours?"

Her eyes widening with surprise, Elsa felt tears well up in her cheeks. She then smiled, before hugging Anna tightly. "Nothing would make me happier, Anna," she said softly. "I will gladly be your queen."

The two then pulled away, as Anna then cupped her sister's cheeks and pulled her into a soft, loving kiss, finally glad they were going to make good on their promise from all those years ago.

xXx

 **Author's note:** Awwww, this was just an adorable one to do! Hope you enjoy!


End file.
